Need some help and direction on my transmission issue. 130k miles on a highly maintained GL550 with just 2k miles on the latest tranny oil change. Never had a shifting issue and yesterday down shifted into first really hard (drove 100 miles before this no problem ) and than the second stop went into 2nd limp mode. Got home after 8 mile drive and pulled 0893 code.
Looked for any leaks ..took a few ounces of tranny fluid out.. clean like new no smell. Reset code and took for a test drive.. shifted 1-2-3 gear than threw code .. reset than no reverse..drove up the drive in first and no reverse NO CODES.. shutoff and restarted with a reverse ?? NO CODES? I am getting a little lost and feel like I should start with valve body issue?? Anybody have anything similar or add to my direction thanks Bill

 

Was the tranny fluid drained only (drop and clean pan, replace filter, refill), was the torque converter also drained in addition to above, or flushed - oil lines/cooler in addition to above two.

How much fluid was drained and how much refilled?

If you shift manually is the tranny shifting as hard into first?

 

2k ago, did they use the correct fluid?

 

Torque converter was drained. panned cleaned, new filter and gasket . Amsoil approved fluid . I maintain 6 MB’s including 3 SUV’s with 722.9.
Torque converter was drained . I use the pump method with temp 113 F .. less than 1/2 qrt came out. I have done approx 10 ..722.9 oil changes with the same method. This was the second change on this vehicle .. bought at 80k miles and changed than 45k miles later both times used approved Amsoil. The car goes between being stuck in 2nd and 1st now. Using my Star system it quit throwing codes. I cannot find much info on error 0893… any help? thanks Bill

 

The 7G came out in 2003, and a 2008 is somewhat new-ish in its production lifespan.

Slamming into gear (gear change happening too fast/quickly/uncontrolled) suggests a hydraulic control problem, this mainly is handled in the conductor plate.

Conductor plate failure and replacement is one option. Need to rule out other potential failures.

Do more test driving and try to hold gear using paddles and light throttle. Do this throughout the speed range and hold gear for a good amount of time (1 minute or so). Continue the test and map out each gear change up and down and isolate the problem. All under light throttle.

If you don’t have XENTRY you should have it. You can go into the transmission module and see adaptations. If the adaptations are to the edges of the adjustment windows it will give you direction. An indy shop can do this for you for a diagnostic fee.

 

No paddle shifting. Stuck in either 1st or 2nd.Won’t shift and quit throwing 0893 error. I feel very strong that it is a Valve body issue.
My next plan is to put it back on the rack and run it.. crack a tranny line loose and see if it has pressure..if yes drop the valve body assembly and look for broken shift lever or stuck pistons???
I was just throwing this issue out there hoping someone knew something about error code 0893? thanks for the help. Bill

 

Never seen or heard of that code if you put it on xentry and are unable to interrogate the transmission control module that’s also a clue towards the valve body having gone bad, and by gone bad I mean the contactor plates have gum or gotten too dirty to conduct signal voltage.

There are anecdotal stories of being able to clean the contactor plates with electrical cleaner refilling fluid per the WIS and enjoying forward motion for a limited period of time.

 

I can still read the module and run test. It quit throwing codes?? Really bizarre and just all of a sudden … a couple of hard downshifts and wham limp mode.

 

Sounds like hydraulic blockage in the valves. If electrical checks out / no codes / full communication it suggests speed sensors are ok but shifting elements (valves) may not be ok.

 

Exactly what I am thinking . History bought with 80k miles and instantly did a full tranny oil change with torque converter … 45k miles later did another and it was real clean this time. But first change at 80k was horrible . Even put a new transmission pan on it because of rusty outside.
First code 0893…. indicates a possible valve body but very vague. One post on another forum stated everytime he gets a 0893,0894 he replaces the valve body instantly .
Do you know anything about the National Pro..Valve Body Pro rebuilds? I am going to try and use my TCU/TCM and put it on a rebuilt Valve body..thanks Bill

 

Anybody have recommendations for rebuilt valve bodies for the 722.9 and still using my TCU/TCM? thanks again

 

Try searching this site. From memory there was a place in SoCal that does exchanges. Search will find it.

 

I dropped the valve body today but definitely looking like a failing torque converter .. moving it from one garage to another and testing driving in the driveway.. starting out in first gear takes 2500 rpm and it hits hard like a race car stall tranny . Found a couple solenoid Orings cracked B1 brake … removed pistons/spools from valve body and it is spotless very clean oil in the valve body… seeing some real fine metal in the pan and it was spotless 2k miles ago?? any thoughts on torque converters ? thanks Bill

 

Look up B1/B2 clutch pack failure.

 

Took all the pistons/spools out ..they were spotless and not stick or broken springs. Took out the 8 solenoids and found B1 had a bottom Oring ripped. Replaced all 16 Solenoid Orings with FKM 75 material . Shifts great and No error codes. The B1 brake solenoid not allowing proper gears to go in threw the code that stated Hydraulic problem and 2 gears going in. All lower Orings looked bad.
My son has a large Ebay store for T129 chassis and I will have Oring kits 16 qty and the 2 orange Silicon electrical plug Orings. MB will not sell the Orings and will only sell the complete Solenoid. I have sized them and inquired about the best material so both will be FKM 75 material. I believe some of the older 722.9 valve bodies have cold weather issues. Here in ohio we had a number of -5 to -12 degree days. Some Viton is only good for +5 degrees.
Ok thanks for any help and ideas. Bill

 

So then please let us know if you previous to this had the neck snapping harsh 2-1 downshift when cold - I believe this is what precedes the larger failure you had here.

 

Yes that is exactly what happened.Hard down shifting 2-1 than the next stop sign ..another hard down shift and limp mode to second .
Except it was after 100 miles driven that day so the tranny was not cold. We have had extremely cold weather here and I am guessing that the extreme cold weather might have something to do with the small blue Orings failures. Bill

 

Hello vesiadog,

Can you post the link where we can find the 16 solenoid O-rings.
Thanks

 

Try Cobra Transmission first . Let me know if they have stock ok

https://cobratransmission.com/722.9-Solenoid-Oring-Kit
https://cobratransmission.com/722.9-Case-Connector-Oring

 

Thank you for your quick reply.
I know Cobra Transmission, but the shipping costs for France are expensive ($37).
do you know another site?
or better yet do you know the dimensions of these o-rings?
Thank you very much for your interest in my research.

 

2mm x 14.5mm V75 FKM
1.5mm x 8.5mm V75 FKM
for my GL550 I used 8 of each. So far so good.

 

Hey vesiadog,
You are the best, the best, the best ...

I assume the dimensions are: CS x ID
Thank you very very very much